So,
Some time ago I found a video about Hydroponic systems again, this time
it was about small-scale "for window" installations of horizontal sets
of pipes, with a tank, regulator and pump system. This got me thinking
about space and my balcony, and I started researching into Horizontal
systems, rather than vertical.

There's a few out there, most are really rudimentary (plastic bottles)
or rather large scale, but I didn't find much documenting if they work
or not, and how well they work and not. So I set a budget, and started
to plan the project proper.

First my idea was to use a single, 2m tall, 100mm diameter PVC pipe, and
drill holes into it, inserting small pots for the plants. After checking
the basic math that told me that I'd have approximately 160 litres of
volume in such a pipe, along with how much work I'd have to be doing to
cut the holes, I went another route.

In the bottom of the barrel, I put some thoroughly cleaned ( and
boiled)
stones, in
order to make it a bit heavier.

For the water flow, I went with a very simple
pentry-pump
for boats/freshwater tanks (7.5 litres/minute, 12Volt, 2 ampere, meaning
around 24watt).

Filling: I used a mix of Leca ( for the main pipe) and
Perlite (for the small
outliers). From the beginning I was going to use coconut shreds, but I
couldn't find any locally, so Leca it was.

Note here, that the Leca I got I had to rinse quite a few times in order
to get the dust off. Much of it was quite messy, and would have killed
my little pump in no-time. I'm still not sure how long that pump will
live, but that is something for the future to tell.

In the bottom of the pipe, I cut a few
openings
in order to let water flow through. It turns out that these were not
wide enough in practice, and when I turned on the pump, water would fill
the pipe up to the middle, and overflow. This was solved by taking the
whole thing apart, pulling it up and drilling holes into the bottom pipe
to let more water through. Not a fun thing, and no pictures were taken
then, as I was already getting very wet.

The water flow turned out to be too much anyhow (7.5 litres/minute is a
lot, it turns out) so instead of driving it at 12V, I'm running it at
5-7 volts of power, causing a much more manageable water flow. Also, it
turns out that the layer of perlite I was using for the small pipes
flowed down into the main pipe, expanded in the water, and made water
throughput low enough that I had water running everywhere when I was
pumping full speed.

Right now, the hose from the bottom to the top is fastened with
rubber-bands and tape, I figure something more long term may be needed.
I also added a cloth filter to the top to avoid too much junk to fall in
there.

Currently, the system is running on a timer to stimulate ebb/flow
control, but I have yet to figure out how to do it, so right now its 2
hours on, 1 off during the day, and 15 minutes on/ 2 off during the
night. If this turns out to be wrong, well, shan't be too hard to fix.

Now? My seedlings aren't quite done yet, so I have a hard time planting
anything in this, until then, I'll have to see how this goes. The plan
is to use easy herbs/salad this year, and maybe strawberries in the
future.